[An unusual pneumomediastinum case in a child caused by spontaneous bronchial rupture]. / Un insolito caso di pneumomediastino in un bambino da rottura spontanea di bronco.

We report a case of spontaneous pneumomediastinum (SPM) in a 3 year-old child, admitted to the emergency department because he presented dyspnea for a few hours, after a paroxysm of cough. The SPM is rare in children; the term "spontaneous" is reserved for cases of pneumomediastinum that haven't a traumatic cause. SPM is seen most commonly in asthmatics and in any patient who induces a Valsalva maneuver. The clinical diagnosis is confirmed by chest radiograph. When the diagnosis is uncertain, the chest CT scan is considered the gold standard of imaging tests, capable of detecting pneumomediastinum even in patients with small amounts of mediastinal air. In this case CT images showed the cause: spontaneous bronchial rupture. The direct sign of bronchial injury is the contiguity of the luminal air with that in the mediastinum. In the literature SPM cases are very rare, at least in health patients without tracheobronchial anomalies. The SPM is generally a benign entity that requires supportive care, and resolution occurs spontaneously, such as in our patient. In this article we want to explain the main clinical, diagnostic and therapeutic aspects of SPM, because, even if it's rare in children, it must be considered in the differential diagnosis of dyspnea; then we want to demonstrate as, in this case, a TC scan was important to identifying the SPM cause: a bronchial rupture.

[A sign of the changing times: neonatal scabies]. / Un segno dei tempi che cambiano: scabbia neonatale.

Scabies is an itchy-parasitic cutaneous infection; it can spread from person to person directly or through clothing, sheets or mattresses. The incidence had fallen a lot during the last ten years, but recently it is growing up again; this is due to immigration of people coming from countries where local hygienic and social conditions are very poor. In this contest it is more frequent to observe the infection in pediatric age, sometimes also newborn. In this particular case the diagnosis can be more difficult because the clinical manifestations are different from pathognomonic lesions we usually see in adult age. We report the clinical case of a newborn, 30-day-old, born in Italy from an Indian family. When the baby was admitted in our department she looked in good physical conditions but she presented a pustular dermatitis all over the body, scalp excluded. The presence in the mother of typical skin lesion and baby's eosinophilia at blood test, induced us to suspect the diagnosis of scabies. However, both the search for acarus at optical microscope on a skin sample obtained with "scarification" and clinical response to a treatment with PAF, were unsuccessful. Moreover, we found in the baby a persistent trombopenia; this fact induced us to think of other hypothesis. Finally the child's positive response to permethrina topical treatment and normalization of the number of platelets let us confirm the initial diagnosis of scabies.

Programmable CSF shunt valves: radiographic identification and interpretation.

The programmable CSF shunt valve has become an important tool in hydrocephalus treatment, particularly in the NPH population and in pediatric patients with complex hydrocephalus. The purpose of this study is to provide a single reference for the identification of programmable shunt valves and the interpretation of programmable shunt valve settings. Four major manufacturers of programmable shunts agreed to participate in this study. Each provided radiographic images and legends for their appropriate interpretation. Issues of MR imaging compatibility for each valve are also discussed.

Congenital adenohypophysis aplasia: clinical features and analysis of the transcriptional factors for embryonic pituitary development.

UNLABELLED: Anterior pituitary agenesis (APA) has very rarely been reported. Therefore, its phenotypical and genotypical features are not well known. The aim of this study was to ascertain whether the clinical picture in 4 subjects with APA and multiple pituitary hormone deficiencies (MPHD) was different compared to the one observed in a selected control group consisting of 7 MPHD individuals with hypoplastic (and not aplastic) adenohypophysis and pituitary stalk interruption syndrome. Another goal was to investigate genetic basis of APA by analyzing for the first time in this condition many of the transcriptional factors which are required for both structural development and cellular differentiation of hypophysis. Age at diagnosis was significantly lower in APA children than in controls (1.5+/-2.3 vs 11.1+/-7.6 yr, p<0.0005). Microphallus and neonatal cholestasis were observed only in APA subjects (chi-squared=4.3, p<0.05) and also neonatal hypoglycemia was more frequent in APA patients than in controls (X2=4.05, p<0.05). Molecular analyses of the genes of the transcriptional factors POU1F1, PROP1, LHX3, LHX4, ISL1 and HESX1 detected no mutations in APA patients. CONCLUSIONS: a) if compared with a selected cohort of MPHD patients with both adenohypophysis hypoplasia and pituitary stalk interruption syndrome, the ones with APA show an earlier and more severe picture of hypopituitarism; b) mutations in several transcription factors that are known to be essential for the development of Rathke's pouch are not necessarily found in humans with APA.

The influence of the extracellular matrix on the morphology and intracellular pH of cultured astrocytes exposed to media lacking bicarbonate.

In previous work we showed that the polygonal shape of hippocampal astrocytes cultured on poly-L-lysine changes to a stellate morphology with loss of actinomyosin stress fibers on exchanging the culture medium for saline buffered with HEPES [Brain Res 946 (2002)12]. By contrast, in bicarbonate-buffered saline containing Ca(2+) astrocytes remained polygonal and continued to express stress fibers. Evidence suggests that stellation induced by saline buffered with HEPES is related to intracellular acidification due to the absence of bicarbonate. Here we studied the influence of the matrix used in preparing astrocyte cultures. Stellation in HEPES-saline occurred on a matrix of fibronectin, but not on matrices of collagen I or IV provided Ca(2+) was present. Laminin partially prevented stellation in HEPES-saline. Further, the intracellular acidification induced by HEPES-saline observed in astrocytes cultured on polylysine was abolished in cells cultured on collagens and was attentuated on a matrix of laminin. Two observations suggested the involvement of integrins and focal adhesions. (1) Treatment of cultures on collagens with a blocking antibody to the beta1 integrin subunit abolished protection against HEPES-induced stellation. (2) Compared with polylysine, astrocytes cultured on collagens expressed increased contents of phosphotyrosine proteins, focal adhesion proteins vinculin and paxillin, the beta1 integrin subunit and increased numbers of focal adhesions labelled with anti-vinculin. The observation that astrocytes cultured on collagen I or IV, in contrast to polylysine, express stress fibers and a constant intracellular pH in the absence of buffering by bicarbonate may be related to the fact that in the intact brain astrocytic processes (or end-feet) encounter and bind to collagen IV and laminin in the basement membrane of the endothelial cells which surround the cerebral capillaries. It is also possible that astrocytes retain this capacity from early development when fibrous matrix proteins are present.

Hydrostatic balloon dilation of congenital esophageal stenoses associated with esophageal atresia.

It has been stated that congenital cartilage rings in the esophagus do not respond to dilation and should be resected. The authors report on 3 infants with congenital esophageal stenoses who were treated successfully with hydrostatic balloon dilation. Based on the appearance during dilation the authors believe that these stenoses were cartilage rings. The technique is described in detail. Balloon dilation is the treatment of choice for these patients. Resection should be reserved for those who do not respond to this form of therapy.

Does the reticular thalamic nucleus project to the midbrain?

In this study, we investigated whether the reticular thalamic nucleus has a projection to major centres of the midbrain in rats, rabbits and cats. Various tracers (biotinylated dextran, cholera toxin B subunit, fluorescent latex beads) were injected either into the midbrain tectum (deep layers of the superior colliculus) or tegmentum (midbrain reticular and pedunculopontine nuclei). In other experiments, different coloured latex beads (red and green) were injected into the deep layers of the superior colliculus and into the midbrain reticular nucleus of the same animal (rabbits). Our major finding is that in rats, rabbits and cats, there are no retrogradely labelled cells in the reticular thalamic nucleus after tracer injections into the above mentioned midbrain centres. In rabbits and cats, however, there are retrogradely labelled cells lying close to the ventromedial edge of the reticular thalamic nucleus after such injections. We show, by means of immunocytochemical double-labelling, that these retrogradely labelled cells do not lie in the reticular thalamic nucleus as suggested by previous studies, but in the inner small-celled region, a group of small cells that forms part of the zona incerta. Although these appears to be no clear topography of projection of the inner small-celled region, our tracer double-labelling experiments show that separate cells in the inner small-celled region project to individual centres of the midbrain (i.e., there are very few double-labelled cells after double injections). In rats, unlike in rabbits and cats, there is no clearly defined inner small-celled region and there are no retrogradely labelled cells seen along the ventromedial edge of the reticular thalamic nucleus. Our results suggest that in rats, rabbits and cats, there is no projection of the reticular thalamic nucleus to major centres of the midbrain, suggesting that the nucleus may not have a very strong influence on midbrain function, as it does on dorsal thalamic function.

Prenatal ultrasound characterization of the suprarenal mass: distinction between neuroblastoma and subdiaphragmatic extralobar pulmonary sequestration.

With the increased routine use of prenatal ultrasonography, subdiaphragmatic masses in the fetus are identified more frequently. Suprarenal masses often are presumed to be neuroblastoma and are removed surgically postnatally. We sought to better understand the natural history of subdiaphragmatic extralobar pulmonary sequestration, and to determine if subdiaphragmatic extralobar pulmonary sequestration can be distinguished preoperatively from neuroblastoma. The literature was reviewed for cases of prenatally diagnosed suprarenal masses that proved ultimately to be either subdiaphragmatic extralobar pulmonary sequestration or neuroblastoma. The distinguishing features of the two lesions were identified and an algorithm was created on the basis of these distinctions. Prenatally diagnosed subdiaphragmatic extralobar pulmonary sequestration is no longer rare, with one case being reported for every 2.5 cases of neuroblastoma. On prenatal ultrasonography subdiaphragmatic extralobar pulmonary sequestration usually is echogenic, is left-sided, and can be identified in the second trimester. Neuroblastoma is most often cystic, right-sided, and identified in the third trimester. In summary, subdiaphragmatic extralobar pulmonary sequestration must be considered in the differential diagnosis of the suprarenal mass identified on prenatal ultrasonography. Using the algorithm which we propose, the correct diagnosis can be determined prenatally in 95% of patients.

Warping CT scans from nontreatment to treatment position.

This paper describes a cost-effective technique that optimally utilizes all available diagnostic studies for three-dimensional treatment planning. A simulator unit modified to produce cross-sectional images (simulator-CT unit) is used to create a reference data set with the patient in the treatment position. Registration software (qsh) brings other diagnostic studies into agreement with this reference data set. Two cases are presented as examples of the use of this technique. Registration of abdominal scans from the same patient demonstrates the warping of a nontreatment position study to the treatment position. The second case is based on paired data sets through the head, in which the diagnostic study was obtained by using a gantry tilt to follow the base of the skull and to avoid sections passing through the teeth. The registration software provides a method for combining diagnostic studies into a single "master" data set. The success of the transformation depends on the operator's ability to identify corresponding anatomic landmarks for different data sets and on the magnitude of the variation in the patient's position from one procedure to the next. Limitations in image quality and the number of cross-sections obtainable from a simulator-CT unit can be partially overcome by using the described technique. Thus, the information contained in nontreatment position diagnostic tests can be used accurately for treatment planning at limited cost.

Reticular thalamic region in the rabbit: organisation of efferents to the superior colliculus.

Although it is well-established that the reticular thalamic nucleus provides a strong GABAergic input to the dorsal thalamus, the existence of reticular efferents to other subcortical centres is less certain. In this study, we investigate whether the reticular nucleus projects to a major brainstem centre, the superior colliculus. The neuronal tracer, biotinylated dextran, was injected into superficial and deep layers of the superior colliculus of rabbits and the resultant labelling in the reticular region was examined. After large injections, which encompassed both superficial and deep collicular layers, two discrete populations of retrogradely labelled cells are seen in the region of the reticular nucleus. One population of retrogradely labelled cells lies in the dorsocaudal regions of the reticular nucleus, the classically defined visual sector. This group of retrogradely labelled reticular cells is also seen after injections into the superficial layers of the superior colliculus, but not after injections limited to the deeper collicular layers. The other population lies close to the ventromedial edge of the main body of the reticular nucleus, within a region referred to as the inner small-celled region. This group of small cells has been commonly thought to be part of the reticular nucleus, but our immunohistochemical studies suggest that this is a clearly separate region, a region continuous ventrally with zona incerta. The retrogradely labelled cells in the inner small-celled region are seen also after injections limited to the deeper collicular layers, but not after injections limited to the superficial collicular layers. Our results suggest functional heterogeneity within the reticular nucleus: Specifically, it suggests that the nucleus is in a position to influence the processing of visual information at both the dorsal thalamic and midbrain levels.

NADPH-diaphorase reactivity in adult and developing cat retinae.

We have examined the distribution and size of nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase reactivity in adult and developing cat retinae. From late gestation E (embryonic day) 58 to adulthood, NADPH-diaphorase reactivity was detected in amacrine cells with somata located in the inner nuclear layer (INL) and ganglion cell layer (GCL) and in processes spreading in the middle strata of the inner plexiform layer (IPL). Reactivity was also present in small rounded profiles located in the outer plexiform layer (OPL) and thought to be cone pedicles. The number of NADPH-diaphorase reactive cells present in adult retinae was about 40,000, 75% of these somata were located in the GCL, the remainder in the INL. At birth, however, there was more than double this number of labelled somata (85,000), the total gradually declining to reach adult values by P (postnatal day) 25. This loss of NADPH-diaphorase reactive somata may be partly explained by natural cell death (apoptosis) or by loss of the active diaphorase from the cells. The density distributions of NADPH-diaphorase reactive cells in the INL and GCL of retinal wholemounts reached maxima in regions slightly inferior to the area centralis at all ages studied. The principal topographical difference between adult and developing retinae was that the density gradient of NADPH-diaphorase reactive cells was steeper in adults than at younger ages. During early development, the somal and dendritic field diameters of NADPH-diaphorase reactive cells at the area centralis were about the same size as those in the periphery; by adulthood, cells in the periphery were larger. The change in the somal diameter gradient apparently emerged because of a reduction in somal size of the centrally located cells. The change in the dendritic diameter gradient emerged because of a greater growth of peripheral cells as compared to central cells. We suggest that NADPH-diaphorase may have a role in the formation of synapses in the developing IPL.

Distinct patterns of distribution among NADPH-diaphorase neurones of the guinea pig retina.

We have examined the morphology and distribution of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-diaphorase) cells in the retina of the guinea pig. Two morphologically distinct classes of labelled cells were detected, one with larger, darkly labelled somata commonly located in the inner nuclear layer (INL: NDa cells) and the other with smaller, lightly labelled somata in the ganglion cell layer (GCL: NDb cells). The somata of NDb cells did not vary in diameter with eccentricity, whereas those of the NDa cells were smallest in the visual streak. The number of NDa cells was approximately 3,500, with a mean density of 26/mm2 and NDb cells numbered approximately 4,400, with a mean density of 33 mm2. NDa cells were distributed relatively uniformly across the retina, whereas NDb cells concentrated in the visual streak and were restricted to the superior half of the retina. In these features of morphology and distribution. NADPH-diaphorase neurones of the guinea pig retina are distinct from those observed in other species. It remains to be elucidated whether the diversity in the morphology and distribution of NADPH-diaphorase neurones between species reflects a diversity in their function.